It is currently estimated that one out of 7 women in the United States will develop breast cancer in their lifetime. This statistic produces a harrowing chill in all women as virtually every American has known someone who has been struck by this deadly killer. More than 150,000 new cases are detected and more than 50,000 deaths occur each year in the United States.

Causes of breast cancer

The rate of breast cancer is typically 5 times higher for women in the United States compared to women in other parts of the world. Genetics are an important risk factor, but in most cases a genetic predisposition is secondary to dietary, lifestyle, and environmental factors. In other words, breast cancer risk is largely a result of diet and lifestyle. It is interesting to note that in Japan the rate of breast cancer is about 1/5th the rate in the United States, but in second or third generation Japanese women living in America who eat the Standard American Diet (SAD) the rate of breast cancer is identical to other women living in the United States. 1 Table 1 provides a list of factors that have been linked to breast cancer.

Table 1. Possible Causes of Breast Cancer Genetic factors

Hormonal factors (increased estrogen exposure)

Early onset of menstruation

Pregnancy late in life or no pregnancy

Late menopause, Shorter menstrual cycles

Environmental factors

Xenoestrogens (synthetic compounds which mimic estrogen)

Pesticides, herbicides, halogenated compounds, etc.

Lack of sunlight

Power lines, electric blankets, radiation, etc.

Iatrogenic (Doctor induced)

Oral contraceptives

Hormone replacement therapy

Radiation (diagnostic and therapeutic)

Chemotherapy

Lifestyle factors:

Exposure to cigarette smoke

Body weight (the more overweight you are, the greater the risk)

Exercise level (women who exercise have a reduced rate)

Alcohol and coffee consumption

Dietary factors

Increased saturated fat

Decreased antioxidants

Decreased dietary fiber

Decreased alpha-linolenic acid and omega-3 fatty acids

Decreased "phytoestrogens"

Dietary Factors in the Prevention of Breast Cancer:

Dietary factors appear to be one of the critical aspects in the prevention of breast cancer. The research is a bit muddy because investigators often look only to dietary factors in the United States. For example, let's take a look at the research on saturated fats and breast cancer. It is difficult to determine true risk when looking at women in the United States because the lowest percentile for saturated fat intake in the United States often translates to the highest percentile in other countries. To gauge all dietary risk factors in breast cancer it is extremely important to examine data from a global perspective. This assessment was done recently. The results provide some sound evidence as to what dietary factors appear to promote breast cancer and those that appear to be preventive.

One of the most interesting aspects of the population study was the tremendous protective effect of fish consumption. Fish, particularly cold-water fish like salmon, mackerel, halibut, and herring, are rich sources of the omega-3 fatty acids. This group of fats have shown tremendous anticancer effects against breast cancer in experimental studies. In contrast, the omega-6 fatty acids found in most animal products as well as common vegetable oils such as corn, safflower, and soy, are associated with promoting breast cancer in experimental studies.

2. Flaxseed Oil: Protection

In addition to a diet which features fish, supplementing the diet with flaxseed oil appears to offer significant protection against breast cancer for a couple of different reasons. First of all, flaxseed oil contains nearly twice the level of omega-3 fatty acids as fish oils. In one study, 121 women with initially localized breast cancer examined the association between the levels of various fatty acids in the fatty tissue of the breast and how much the cancer had spread (metastasized).

3 Breast tissue analyzed at the time of surgery indicated a low level of alpha-linolenic acid (18:3n3), the key fatty acid found in flaxseed oil, was associated with the spread of the cancer into the lymph nodes of the armpit as well as tumor invasiveness.

After 31 months of follow-up after the initial surgery, 21 patients developed metastases of their cancer into other body tissues. Low levels of alpha-linolenic acid was the first determinant of metastases in these patients. In other words, when all factors were considered, low levels of alpha-linolenic acid was found to be the most significant contributor to the spread of cancer. Since the main cause of death in breast cancer patients is the development of cancer in other tissues, the significance of this finding is of extreme importance. The results from this study suggest that supplementing the diet with flaxseed oil (approximately 58% alpha-linolenic acid) may help prevent breastcancer, tumor invasiveness, and metastasis.

Flaxseed: Nature's Richest Source of Lignans

In addition to alpha-linolenic acid, flaxseeds and flaxseed oil are also the most abundant sources of lignans. These components are fiber compounds that are capable of binding to estrogen-receptors and interfering with the cancer-promoting effects of estrogen on breast tissue. Exposure to estrogens are a major risk factor for breast cancer. Therefore, foods containing "phytoestrogens" -plant compounds capable of binding to estrogen receptors - such as soy and whole grains are thought to protect against breast cancer by occupying estrogen receptors on breast cells. In addition to competing with estrogen for binding sites on breast cells lignans increase the production of a compound known as sex hormone binding globulin that regulates estrogen levels by escorting excess estrogen from the body. Population studies, as well as experimental studies in humans and animals, have demonstrated that lignans exert significant anticancer effects.

In an animal experiments, flaxseed oil or flaxseed demonstrate significant reduction (e.g., greater than 50% reduction) in tumor numbers and size after one to two months.

4 The Glucuronidase Factor

One of the key ways in which the body gets rid of estrogen is via attaching glucuronic acid to the estrogen in the liver and then excreting this complex in the bile. Glucuronidase is a bacterial enzyme that uncouples (breaks) the bond between excreted estrogen and glucuronic acid. Not surprising is the finding that excess glucuronidase activity is associated with an increased cancer risk, particularly estrogen-dependent breast cancer. The activity of this enzyme is increased when the diet is high in fat and low in fiber. The level of glucuronidase activity may be one of the key underlying factors explaining why certain dietary factors cause breast cancer and why other dietary factors are preventive.

The activity of glucuronidase be reduced by establishing a proper bacterial flora by eating a diet high in plant foods and supplementing the diet with the "friendly bacteria" Lactobacillus acidophilus and Bifidobacterium bifidum. Other dietary factors which can dramatically reduce the activity of this enzyme are the consumption of onion and garlic, and foods high in glucaric acid like apples, brussel sprouts, broccoli, cabbage, and lettuce. Glucaric acid in a pill form, calcium D-glucarate may turn out to be the "magic bullet" in the prevention of breast cancer, especially in women who have already battled breast cancer. Preliminary research is quite encouraging.

5 Currently, women with a history of breast cancer are prescribed the drug tamoxifen. This drug is associated with numerous side effects and is quite controversial in its overall effectiveness. In contrast, calcium D-glucarate is completely safe and, if preliminary results hold true, more effective. Calcium D- glucarate is currently being investigated at the Memorial Sloan Kettering Cancer Center in New York. It is just entering the health food market as well.

Final Comments

Given the epidemic nature of breast cancer, it is essential that every woman in America take steps to learn how they can prevent this often deadly disease. Primary prevention involves reducing controllable risk factors, adhering to a healthful lifestyle, eating a diet consisting primarily of protective factors, consuming one tablespoon of flaxseed oil daily, and taking additional antioxidant nutrients (e.g., vitamin C: minimum 500 mg day; vitamin E: minimum 400 IU day). In high risk individuals, I would also recommend taking a high quality L. acidophilus and B. bifidum product (approximately 2 billion live bacteria per day) and calcium D-glucarate (500 to 1,000 mg three times daily).